Jonny Heinkenwrote a review of Castelli Mortirolo 4 Jacket - Men's on November 15, 2017
Familiarity: I've put it through the wringer
Castelli is based in the foothills of the Italian Alps (Dolomites). They know winter cycling.
Application: Castelli officially rates this jacket for use in cold, dry weather from 60° down to 42° F. This is fantastic as this is the temperature range the majority of us ride in the Winter (in the 40s).
1. The clever, innovative, front chest vents. These provide great versatility! For example, close the vents and select a winter-weight baselayer, ride hard, and this jacket will keep you warm down to about 40-35° (temp sensitivity is individual).
Yet, with the vents open and a light-weight baselayer on, this jacket also works up to 60°. Awesome.
2. Authentic Gore Windstopper textile is simply the best in the business. It is non-flapping, insulating, windproof, and water-resistant; yet breathable. So it protects fantastic against cold but also vents away sweat build-up extremely well. So no dreaded "sweat in a bag" occurs in this jacket.
3. Also, Windstopper provides a soft and snug (and quiet) 'aero' fit. This jacket does NOT flap in the wind.
The overall performance and versatility of the Mortirolo jacket is benchmark in this temp range.
Cons: The Mortirolo protects well against fog, mist, and drizzle. But Windstopper is not waterproof. So, if the weather is threatening full-on rain, take along a light, taped, dedicated rain shell (like the Superleggera, Tempesta, or Dolomiti).
***Sizing: As castelli vets know, Castelli runs small. Italian sizing -is- different than US sizing. So, size up +1 here from your normal street size. Still, the Mortirolo will fit snug (as it is designed to).***
PS. _The Mortirolo Pass is one of the highest and most famous climbs in Europe. It is a legendary stage at the Giro d'Italia.